NASA finds multiple habitable episodes in Jezero Crater, Mars

NASA's Perseverance rover has found minerals that indicate Jezero Crater on Mars experienced multiple episodes of flowing water, creating habitats that could have supported life. The rover's latest survey identified about two dozen mineral types signaling a dynamic history of volcanic rocks altered by liquid water, revealing three distinct episodes of fluid activity at Jezero.

Lead author Eleanor Moreland, a Rice University graduate student, said the minerals 'support multiple, temporally distinct episodes of fluid alteration' and indicate more than one time when Jezero hosted environments potentially suitable for life. The first group of minerals—greenalite, hisingerite and ferroaluminoceladonite—formed in hot, acidic water confined to the crater floor, a harsh environment least favorable for life.

The second group formed in moderate, near-neutral water and covered a larger area, with Minnesotaite found on both the crater floor and the upper fan region and clinoptilolite appearing on the crater floor. The third group formed under low-temperature, alkaline conditions and was widely distributed, with sepiolite indicating a widespread episode of liquid water and sediments infilling Jezero. Moreland added, 'These minerals tell us that Jezero experienced a shift from harsher, hot, acidic fluids to more neutral and alkaline ones over time, conditions we think of as increasingly supportive of life.' Co-author Kirsten Siebach, assistant professor of Earth sciences, noted, 'These hot, acidic conditions would be the most challenging for life. But on Earth, life can persist even in extreme environments like the acidic pools of Yellowstone, so it doesn't rule out habitability.'

To interpret the data, the team used the Mineral Identification by Stoichiometry (MIST) algorithm alongside the Planetary Instrument for X-ray Lithochemistry (PIXL). The approach runs repeated mineral identifications while accounting for measurement uncertainties, a strategy the researchers liken to meteorologists running multiple simulations to forecast complex systems. 'Our error analysis lets us assign confidence levels to every mineral match,' Moreland said. 'MIST not only informs Mars 2020 science and decision-making, but it is also creating a mineralogical archive of Jezero Crater that will be invaluable if samples are returned to Earth.'

The findings reinforce that Jezero, once the site of an ancient lake, hosted a complex and dynamic history of water activity. Each mineral discovery helps scientists assess whether Mars ever supported life and informs Perseverance's ongoing sampling plan for potential return to Earth.